set term png font "./simsun.ttc, 9"
set output 'delays.png'

set title "全国各地连接服务器的网络延迟分布"
set xlabel '延迟（毫秒）'
set ylabel '百分比'
set style data histogram
set style histogram cluster gap 1
set style fill solid border -1
unset key
set grid ytics
plot 'delays.dat' using ($1*100):xtic(2)
